Value

Author(s)

References

Cumming, G. & Finch, S. (2001). A primer on the understanding, use, and calculation of confidence intervals that are
based on central and noncentral distributions, Educational and Psychological Measurement, 61, 532–574.

See Also

ci.sc, conf.limits.nct, ss.aipe.c

Examples

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# Suppose the population standardized contrast is believed to be .6 # in some 5-group ANOVA model. The researcher is interested in comparing # the average of means of group 1 and 2 with the average of group 3 and 4.# To calculate the necessary sample size per gorup such that the width # of 95 percent confidence interval of the standardized # contrast is, with 90 percent assurance, no wider than .4:# ss.aipe.sc(psi=.6, c.weights=c(.5, .5, -.5, -.5, 0), width=.4, assurance=.90)